Clinical Research News

STEPping Forward

Surgeons Test New Surgery for Short Bowel Syndrome

Serial Transverse Enteroplasty (STEP) can lengthen the bowel in some patients. The surgeons make multiple incisions into a short, dilated segment to create a longer, thinner segment of intestine. Although the new segment is initially a zig zag in shape, it becomes straight as it heals. art by Nancy Heim

With every advance in medicine, the thrill of discovery also brings a new set of challenges to meet and questions to resolve. For doctors treating short bowel syndrome, the advent of an important surgical treatment, the STEP procedure, is no exception.

Short bowel syndrome is a rare but serious condition that mainly affects newborns and young children. Because of either disease or required surgery, children with this syndrome are left with a shortened small intestine. The loss of intestinal function leaves them unable to digest food or grow as they should. Children with short bowel syndrome may be able to take some food by mouth, but sometimes long-term intravenous nutrition can be necessary. While this intravenous nutrition provides life-saving supplemental calories, it is highly complex and carries significant risks in the long-term. The most serious risks include infection, clotting of major veins and, in some cases, liver failure. These risks spurred a Boston physician to develop an innovative way to lengthen the bowel through a novel surgical procedure.

Described just three years ago, Serial Transverse Enteroplasty (STEP) can both lengthen and taper the small intestine in some patients. During the procedure, a short segment of the intestine is carefully cut and reshaped into a longer, thinner segment. The longer, thinner intestine is thought to function more efficiently and lead to better absorption of food. "This can be an important component in an overall plan for intestinal rehabilitation," says Robert A. Cowles, MD, Assistant Professor of Surgery at Morgan Stanley Children's Hospital of NewYork-Presbyterian.

In light of the success of the procedure in children, some physicians are beginning to broaden the use of STEP to other patients. "The use of STEP is changing," explains Dr. Cowles. But because the procedure is so new, surgeons have not been able to fully sort out which patients will benefit the most, and for whom it may be inappropriate. Dr. Cowles is now tracking outcomes and working to establish clear definitions as to optimum application of the STEP procedure. "It would be easy to apply STEP inappropriately," Dr. Cowles states.

Patients with dilated, shortened intestine are carefully selected as candidates for the STEP procedure. After the procedure is performed, their nutrition is carefully monitored and adjusted. Patients may take nutrition intravenously (into a central vein of the body), by mouth, or through a tube into the stomach or intestine (enterally). As intestinal function improves and more calories are absorbed by the intestine, the amount of intravenous nutrition is reduced. "The final goal is to completely free these children from intravenous nutrition," Dr. Cowles explains. "We encourage patients to take at least some food by mouth, because it actually stimulates growth of the intestine. In cases where advancing oral nutrition is difficult, we recommend placement of a tube into the stomach for more certain delivery of nutrients to the intestine."

In determining eligibility for a potential candidate, the multidisciplinary Intestinal Rehabilitation and Transplantation team uses strict criteria in determining who may be a candidate for the procedure, including shortened intestinal length, dilation of intestine, and lack of severe liver disease.

When employing a new technique, it is important to be creative, but safe, in its applications. For example, the team recently performed what is thought to be the first STEP procedure in a child with short bowel syndrome who had already received a liver transplant. This child's liver failure, caused by long-term intravenous nutrition, initially made him a poor candidate for the STEP procedure. After the liver transplant, Dr. Cowles' team considered the STEP procedure to be safer and an important part of the child's overall intestinal rehabilitation plan. Similarly, in 2004, the team performed one of the first STEP procedures in a newborn baby with a congenital blockage of the intestine.

"The potential benefits of this new surgical procedure are exciting, and the Intestinal Rehabilitation and Transplantation team wants to be certain that it is being offered to as many children who may be able to benefit from it," says Dr. Cowles. "At the same time, it is important to continue to assess and improve the long-term outcomes of these chronically ill children."